Gliomas are an important clinical problem. Prognostic variables include histology (cell type and grade), age, and performance status. Unfortunately, the histology of gliomas is not simple, and pathologists often disagree in their diagnosis. Since diagnosis is an important parameter in patient selection for clinical trials, studies may suffer from entry criteria that are not objective, and comparisons across studies that target these tumors are therefore unreliable. Furthermore, since cases in the community are treated according to these diagnoses, optimal therapy may not ever reach a particular patient. We and others have found that chromosome aberrations occur commonly in these tumors and a pilot study has suggested that some of them are prognostic. This proposal seeks to validate this finding and to determine more particular regions on chromosomes responsible for this behavior. The aims are: 1) Define the minimum recurrent 7q amplicon in grade 3 astrocytomas. 2) Functional characterization of genomic sequence spanning critical region defined in aim 1. 3) Determine whether copy number aberrations (CNAs) and/or small genetic elements on chromosomes 7, 10, 4q, and 12q predict survival in grade 2 and 3 astrocytoma patients.